of Marston Road, Wolverhampton. Telephone: 21666/7/8. Telegraphic Address: "Villiers, Wolverhampton". (1937)
The Argus, Fri 9 Nov 1956
New engine this month Two new 250c.c. Villiers engines have been announced for 1957, a single, starting in November, and a twin which will be available from January 1. For scooters, a 197c.c. model with built-in electric starter and fan cooling came into production in August, and another 150c.c. scooter engine, without starter, will become available next month. Smallest in the range are 98c.c. units with single speed for autocycles, or with two speeds for either hand or foot change. The rest of the range includes 150, 175, and 197c.c. units, with gearboxes up to four speeds.
Ten Villiers Engines For New Season The Villiers Engineering Co. Ltd. of Wolverhampton, has announced that its 1954 range of two-stroke motor cycle power units will total 10 models, comprising one of 98 c.c, four of 122 c.c., four of 197 c.c. and one of 225 c.c.
The outstanding model is undoubtedly the new Mark 1H 225 c.c. unit, which was first an- nounced in connection with the James programme for 1954. An entirely new Francis-Barnett 'Cruiser' has been designed for the engine, and several other lightweight manufacturers are known to be interested. With its clean, symmetri- cal lines the Mk. 1H is the equal in appearance of cer- tain Continental designs which have been held up as examples in the past. The crankcase, primary chain case, gearbox and electric housing blend into a stream- lined egg-shaped unit, and the carburetter is totally en- closed in a cowling with re- mote tickler and built-in air cleaner.
Of 225 c.c. (63 x 72 m.m.), the engine has a compression ratio of 7:1 and is said to develop 10 b.h.p. at 4,500 r.p.m. Internal gearbox ratios are 1, 1.32, 1.81 and 3.06:1, and top gear with the recommended sprockets is 6.07:1.
Crankshaft A departure from standard Villiers practice is the built- up crankshaft assembly, which has circular webs forming internal flywheels. This change was necessitated by the reduction in size (and hence flywheel effect) of the flywheel generator to avoid excessive bulk of the stream- lined side-cover. The reduc- tion in size has been effected by eliminating the ignition coil, condenser and contact breaker from the flywheel assembly and re-locating them outside. none Help
This view clearly shows the clean, Continental-fashion lines of the Villiers Mk. 1H 225 c.c. power unit. This view clearly shows the clean, Continental-fashion lines of the Villiers Mk. 1H 225 c.c. power unit. Each mainshaft runs on two substantial ball bear ings, and it is claimed that this rigid support of the crankshaft results in a very smooth power delivery. The forged steel connecting rod has a roller-bearing big end, using two rows of ¼ x ½ in. rollers. A steel-backed, bronze small-end bush is employed.
The flat-topped piston has two pegged rings, and bronze bushes in the gudgeon-pin bosses. Both the cast-iron cylinder barrel and die-cast light-alloy cylinder head are deeply finned; the spark plug is located towards the rear of the hemispherical combustion chamber. Anti- ringing bridges are cast in between the upper fins on the barrel at front and rear.
A Villiers-built four-speed gearbox is bolted to the rear of the crankcase, giving ac cessibility to the cluster and change mechanism without requiring the crankcase to be split. A neat gear-po sition indicator is situated above the kick-starter, which has an unusually robust rat chet mechanism. A pre stretched endless primary chain and cork-faced multi plate clutch run in oil.
The electrical system has several interesting features. The flywheel generator now has only four windings, one pair providing ignition cur rent and the other pair charging the battery by rec tifier. As the ignition wind ings give more voltage at high speeds than is required for ignition purposes, an ad ditional parallel circuit is taken from the lead between generator and ignition coil to feed the rectifier. Thus, as soon as the voltage from the ignition windings ex ceeds the back E.M.F. of the battery, the 'surplus' vol tage is by-passed and as sists the charging of the bat tery, it follows that igni tion voltage remains subs tantially constant at all speeds.
A key-operated lock is flush-fitted on top of the crankcase to the right of the cylinder. This is not an ig nition switch in the normal sense. but a thief-proof de vice, since in the 'off' posi tion it earths the primary ignition circuit so that the engine cannot be started. Only one alteration has been made to the other en gines in the Villiers range; this concerns the contact breaker, for which an eccen tric-type adjustment has been introduced. Manufac ture of the Mk. 2F 98 c.c. autocycle unit has been abandoned in favor of the Mk. 4F, with its two speeds and streamlined lower half. Of the four 122 c.c. and 197 c.c. units, two of each are competition models. This leaves the standard 12D 122 c.c. engine, the utility 13D of the same capacity, the three-speed 8E 197 c.c. unit and the four-speed 8E/4.
Courtesy Trove NLA
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